The 21st century has already arrived in Hong Kong.

Against the skyline, one massive tower looks like an industrial plant turned inside out, its steel structure visible for miles. Another looks like triangular blades stacked helter skelter. Less extreme but equally impressive monoliths cascade down the mountain. Beneath their imposing mass, smartly dressed men and women zip about on noiseless transit systems. Cellular phones are de rigueur.

But Hong Kong's dragon has another, gentler face. In the shadow of such modern zeal, it is easy to forget that Hong Kong is also a tropical city located at roughly the same latitude as the Hawaiian islands. Palm-filled parks are only a quick taxi ride from the business center of the Central District. A little further are serene bays that are havens for windsurfers and sailors. The 230-plus outlying islands that belong to this bustling metropolis are oases where green prevails and traditions hold fast.

These are the two Hong Kongs, one sleek and pulsating with power, the other a haven of old-style Chinese life. The two are shoved together, often side by side, creating a curious and exciting city. The excitement is heightened by anticipation of 1997, when the British will relinquish Hong Kong's control to China.

Even a quick glance reveals the fast-paced city of luxurious hotels, custom suits and endless jewelry shops, whose 5.9 million residents own the highest number of Rolls Royces per capita and drink the most cognac per capita of any culture in the world. The traditional side is more subtle, and clearly fading since I first visited eight years ago. But it still can be seen by visitors who know where to look or who simply take the time to wander.

My own strolls through the colony have led past shops selling such herbal cures as deer's tail tonic tea and into narrow markets where one can pick out a live chicken to take home for dinner. To outlying islands where families live on bright, wooden boats. To a tropical garden, just a quick walk from the business district, where elderly Chinese practice their silent tai chi exercises.

These two worlds collide even in the city's center, Victoria Harbour, buzzing with hydrofoils and fishing boats, tugs and Chinese junks-turned-tourist boats. The harbor is, quite simply, a thrill -- especially at night, when the water glitters with the reflections of the colorful lights of skyscrapers. Though one can transfer swiftly from the business district of Hong Kong island to the shopping mecca of Kowloon on the clean, safe MTR underground system, the seven-minute ride on the Star Ferry is infinitely more charming.

Generally, the closer one is to Victoria Harbour, the more urban the setting. Surely that is true in the area of Kowloon called Tsimshatui, with its Cultural Centre for performing arts, museums, neon that rivals Las Vegas, a profusion of tourist hotels and a Planet Hollywood that opened last spring. Tsimshatui is also the center of the shopper's world. Indoor shopping centers abound, but the cheap deals for which Hong (( Kong was once known are now tough to find. You can now buy camera goods as cheaply in New York, computers for about the same price in a good discount center and leather goods more cheaply just about anywhere else. But the choice of items here is mind-boggling.

I found jewelry to be a better buy here than in the States -- though it is riskier, since one can't easily run back to the jeweler if the stones aren't as valuable as promised. Custom-tailored men's suits and shirts cost about the same as good quality ready-made suits and shirts at home. Though designer styles cost as much or more than in the United States, casual clothes, factory seconds and unknown brands found in smaller shops can be a bargain.

Kowloon is also home to two of the world's most luxurious hotels. The Peninsula is the grande dame of the East, where tea is served each afternoon at 3, a dozen Silver Spur Rolls Royces are available to transport guests and white-gloved bell boys scurry about attending to every need. A new tower slated for completion this year will double the number of rooms to about 300. Just across the street is the Hong Kong Regent, a modern marvel of glass and granite with splendid views of the harbor and equally superb service.

When I first visited Hong Kong eight years ago, Tsimshatui was also graced with pockets of traditional Chinese life. Today, typical markets still exist, though they are farther from the center. In the district called Yaumatei, you can find lanes filled with fruits and vegetables, dried meats and roasted ducks, live chickens and metal shops. At the Jade Market, you can bargain for cheap rings or expensive carved antique pieces. A street market thrives at Temple Street, where each evening shoppers can look for bargains on clothing and munch on shrimp just off the brazier at the Night Market.

Most tourists stay in Kowloon, as I did on my first trip years ago. On my last visit, however, I stayed on Hong Kong island and found myself in a world where surprising quiet and the green smell of lush foliage is just steps away from the business district. Above it hovers Victoria Peak, its 1,785 feet covered with the odd mixture of jungle-like vegetation and residential towers.

As in Kowloon, the area along the harbor bristles with energy. Trams painted with Keith Haring-style graffiti roll past pricey designer shops and jewelry stores. Futuristic skyscrapers filled with offices rise as high as 1,200 feet, wedged between luxury hotels such as the Mandarin, the Kempinski Furama and the Ritz Carlton. Here, too, are vestiges of Hong Kong's colonial beginnings, such as the domed Legislative Council Building.

Even here you can glimpse life on a more human scale, in the beautiful little block called the Chater Garden and in the garden by the city hall, where you may find wedding couples having their photos taken. The Central Market is as authentic as any Chinese area.

Herbal medicine shops are dotted along De Voeux Road as it heads west, toward the city's oldest area. Eight years ago, the streets in this area brimmed with stalls selling dried entrails and squat restaurants where old men rested on tiny wood chairs to take tea. Much of that has disappeared now, but you can still catch a table of men playing mah-jongg. Steep passages leading up the hillside reveal curio shops, snake shops (where you can eat them) and odd street markets. Eventually, they lead to Hollywood Road, home to countless antiques shops and the Chinese temple of Man Mo.

All the flat areas near the water are now covered with offices, shops and restaurants. But the areas above, on the hillside, are ++ residential; here, city dwellers live in apartment towers so narrow they look as if they could fall over. My hotel was one of these, and it was strange to look out my window into the pool of nearby buildings whose tops were often hidden in mist and greenery. The nearby Botanical Garden offered an equally unexpected view: children posing for camera-happy dads and elderly citizens practicing tai chi exercises against the backdrop of orchids, irises, palms and skyscrapers.

Once, getting up the hill to this area, called the Mid-levels, involved a calf-knotting climb up steep streets or a taxi ride up roads created for sedan chairs. The trek is easier now, thanks to a public, covered escalator opened last fall that leads up the hill. But the best ride of all here is the Peak Tram, leading to the tony residential area on Victoria Peak.

The tram ride is an old-fashioned thrill along a narrow-gauge rail that at times is almost scarily steep -- and it goes down backward. At the top are several restaurants and a shopping area in a new tram station.

But the spectacular view is the real reason to come. From here, it seems, you can see all of Hong Kong -- or maybe the world.

It isn't true. Just beyond view is yet another universe -- Hong Kong's outlying islands, where modern furor seems as far away as the moon.

I spent a day visiting two of the largest, Cheung Chau and Lantau.

Cheung Chau is tiny, only about a mile square. But because it is so close to Hong Kong, just 10 miles and an hour ferry ride away, Cheung Chau is home to some 40,000 people. Many of them live literally in the bustling harbor, filled with fishing boats and wooden junks, and it is both charming and strange to see children in their school uniforms taking a skiff home for lunch.

A friend and I rented bicycles and zipped about the village, past stalls filled with incense and bright paper goods and shops selling woven straw hats that are particular to this village. We marveled at the waterfront, cluttered with plastic bins filled with prawns, crabs, mollusks and fish in blues and corals too pretty to eat -- though they are sold for that very purpose. Tight alleys were crammed with stands selling dried shrimp and fruits, medicinal herbs and huge burlap sacks of rice. Motorized carts are used to haul the goods around, we found; no cars are allowed here.

Pak Tai, we learned, is the sea god responsible for this community's prosperity. We stopped at Pak Tai's temple, a simple building where, each May, the Bun Festival is held. The fete is named for 70-foot-high towers of pastry buns built to appease vengeful spirits of pirates who once operated from Cheung Chau. Alas, we would not be there to watch the processions. But we had beaches to investigate and ancient rock carvings to see.

And another isle to explore: Our next ferry ride took us to Lantau island. In years to come, Lantau will be changed by the vast new airport, finally begun after long diplomatic sparring between Britain and China. But for now, Lantau is primarily rural, with fishing communities and monasteries. Much, one hopes, will stay that way.

Too lazy to wait for the bus, we grabbed a taxi and headed out to the far reaches of Tai-O, a small fishing village. Our guidebook advised us of a flat ferry pulled along a rope that would take us to the village itself, situated on an island a few feet across a shallow waterway. An old woman rushed up to take us along, and we were seated in her "sampan" before we realized that this was not the ferry-for-a-few-pennies but a private, $10 tour boat.

No matter. Our gray-haired boat captain carried us off to see the junks that serve both as fishing boats and homes, along with rickety-looking stilt houses. She deposited us on the island village, where we wandered past rows of salted, drying fish and poked our noses among shops seemingly untouched by time.

Our next journey took us to Lantau's primary claim to fame: Po Lin Monastery and its 1,100-foot-high bronze Buddha. But when we finally reached the monastery, the mist was so thick we couldn't see the 250-ton Buddha; we could scarcely see our feet in front of us. The luxuries of the city seemed unbelievably far away.

But they weren't -- and we were back amid the bustle in little more than an hour.

IF YOU GO . . .

Getting there: Many major airlines, including Delta and United, fly to Hong Kong. From the East Coast, the trip typically takes about 22 hours. After August, round-trip airfare from Baltimore to Hong Kong starts around $1,350 f or a week's stay with advance purchase and some restrictions.

Hotels: Hong Kong is full of them, and you can expect to pay about $100 per night for a moderate room. Some of the best-priced options are YMCA and YWCA hotels, which offer nicely appointed rooms.

Information: From dining to shopping, the Hong Kong Tourist Association puts out a publication that can help you. HKTA also allows its member shops to post a sign saying they have agreed to maintain ethnical business practices. Hong Kong Tourist Association, 590 Fifth Ave., New York, N.Y. 10036; (212) 869-5008.